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Magnetic field in materials

  1. Jun 1, 2005 #1
    Hi
    I am trying to derive the relation between magnetic field strength in materials and magnetizing field from the [tex]$\mathbf B$[/tex] field. More exactly, my question is:

    how do we get this expression

    [tex]
    $\nabla \centerdot \mathbf H = - \nabla \centerdot \mathbf M$ \\
    [/tex]

    knowing

    [tex]
    $\nabla \centerdot \mathbf B = 0$ \\
    [/tex]

    and

    [tex]
    $\mathbf B=\mu_0(\mathbf H + \mathbf M )$
    [/tex]
    ?

    Anyone can guid me how the first equation is related to the 2nd and 3rd equations?

    thanku
     
  2. jcsd
  3. Jun 1, 2005 #2
    [tex]\nabla \cdot B=\nabla \cdot {\mu}_0(H+M)=0 [/tex]

    Do you get the idea now?
     
  4. Jun 1, 2005 #3
    I 'm not sure !?

    but how do we get from this:
     
  5. Jun 1, 2005 #4
    [tex]\nabla \cdot {\mu}_0(H+M)=0[/tex]

    divide [tex]\mu_o[/tex] out. you can do that since it's just a constant. then you have

    [tex]\nabla \cdot H + \nabla \cdot M=0[/tex]

    which is what you're looking for once you move the M-term to the other side of the eq.
     
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